SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2593d21aeec3c6f4e0e2a545aa8f3cc3572897508e204f4d5f165f3095f1dea2' 
  AND token = 'yWs3LSr3MOkmbGEbFC8DNSDtNRzBb038qGeCSR4Zn1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}